From Drought to Downpour: How Sudden September Thunderstorms Exploit Dry-Cracked Roof Flashings

September can be tough on commercial roofs. After spending months exposed to intense heat, harsh UV rays, and dry conditions, a sudden thunderstorm can blow in, bringing heavy rain and strong winds along with it. While a sudden downpour may be a welcome relief, this shift in weather can reveal problems that have been developing in your commercial roofing system all summer long.

Flashing is one of the components of your roof that is most vulnerable to extreme rainfall. Prolonged heat and UV exposure can cause flashing materials and sealants to become brittle, crack, shrink, and even pull away from adjacent surfaces. When the weather is dry, you probably don’t even notice these problems, but when several inches of rain fall in a short amount of time, water can quickly seep into even a tiny opening.

With the potential for severe weather, September is a good time to examine the condition of your commercial roof. Understanding how prolonged dry conditions can impact flashing—and how sudden heavy rainfall can exploit those weaknesses—can help you address potential problems before they become costly leaks.

Why Months of Hot, Dry Weather Can Weaken Roof Flashing

While commercial roofs are designed to handle changing weather, excessive heat, long periods of dry weather, and intense exposure to the sun’s harsh UV rays over an extended period of time can take a toll on even the most robust roofing systems. Flashing and sealants, the components that are supposed to protect the most vulnerable areas of your roof, are the most susceptible to damage. Over time, they can lose flexibility, increasing the risk of cracking, shrinking, and separation from the surrounding surfaces.

As time goes on, heat and UV exposure can cause:

• Cracked or split flashing
• Brittle or deteriorated sealants
• Shrinkage around seams and roof penetrations
• Deterioration along roof edges
• Gaps between flashing and adjoining surfaces

What makes things tricky is that these problems don’t always cause immediate leaks. Your commercial roof can appear to be performing properly during a dry stretch of weather while flashing continues to deteriorate. Then suddenly, the first major storm arrives, and you’ve got trouble on your hands. Heavy, windswept rain can find those small cracks and gaps quickly, turning an issue that you didn’t even know existed for months into an active roof leak.

How Heavy Rain Can Exploit Damaged Flashing

Heavy rain doesn’t necessarily create roofing issues. Sometimes, it simply exposes problems that were already there.

During a September downpour, large volumes of water can move across your roof in a short period of time. Strong winds can also drive rain into vulnerable areas. If the flashing has cracked, shrunk, or pulled away from the surrounding surface, water can travel through those openings and work its way beneath the surface. Areas that tend to be the most susceptible to moisture intrusion include:

• Roof-to-wall transitions
• HVAC units
• Skylights and curbs
• Parapet walls
• Drains and other roof openings
• Seams and flashing joints

When water gets under the roof surface, it may not show up directly below the damaged area. It can travel through the roofing system before eventually making its way inside the building. That ceiling stain you noticed? It might not be anywhere near the actual source of the leak. Plus, by the time the stain shows up, the underlying damage may have already spread.

Why Small Flashing Problems Can Cause Bigger Roofing Issues

Flashing may not cover as much surface as the primary roofing membrane, but it plays a vital role in protecting the most vulnerable points of your commercial roofing system. Installed around roof edges, penetrations, transitions, and other vulnerable areas where different materials or surfaces meet, flashing helps prevent water from entering the roofing system through these potential entry points.

These transition points are exposed to weather, temperature changes, and movement, making them more prone to deterioration. Water can easily get through cracks, gaps, or separation and cause widespread damage. Potential repercussions can include:

• Damaged insulation and roofing materials
• Interior water damage
• Mold growth and other moisture-related problems
• Damaged equipment and inventory
• Disruptions to business operations

The longer a flashing issue goes unchecked, the worse the problem will become. That’s why identifying and addressing these problems early is so important.

Prep Your Commercial Roof Before September Thunderstorms

September storms can put serious stress on your commercial roofing system, especially when they roll in after an extended period of hot, dry weather. To avoid serious setbacks and exorbitant repairs, schedule a professional roof assessment. The team of skilled roofing contractors at WaterTight Roofing will perform a comprehensive evaluation, checking for:

• Cracked, damaged, or deteriorated flashing
• Failed or brittle sealants
• Damaged or separated seams
• Loose or damaged edge metal
• Deterioration around penetrations
• Drainage problems
• Signs of previous water intrusion

The goal of a professional roof inspection isn’t to simply find existing leaks. It’s to identify at-risk areas before the next storm and correct them before serious damage occurs.

Is Your Commercial Roof Ready for September Thunderstorms?

The best time to find a roofing problem is before it becomes a leak. A professional commercial roof inspection can identify vulnerable areas so you can have them corrected. At WaterTight Roofing, we help business owners and property managers keep their commercial roofing systems performing their best. Contact us today to schedule a comprehensive inspection and get ahead of potential roof problems.